Apparatus for use in radiocommunication.



L. DE FOREST.

APPARATUS FOR USE IN RADIOCOMMUNICATION.

APPLICATION men 050.11. 1916.

1,299,356. Patented Apr. 1,1919.

To all whom it may concern:

UNITED s'mras PATENT ormcs.

DE FOREST, 01' NEW YORK, N. Y., ASSIG-NOB TO DE FOREST RADIO TELEPHONE AN D TELEGRAPH COMPANY, 01' NEW YORK, N. Y., A CORPORATION OF DELAWARE.

APPARATUS FOR USE IN BADIOCOMMUNICATION.

Specification of Letters Patent.

Patented Apr. 1, 1919.

Application filed December 11, 1916. Serial No. 136,252.

Be it known that I, LEE DE Fomnsr, a citizen of the United States, residing at New York, in the county and State of New York, have made a certain new and useful Invention in Apparatus for Use in Radiocommunication, of which the following is a specification. V

' This invention relates to apparatus for use in radiocommunication.

The object of the invention is to provide a new type of detector.

A further object of he invention is to provide an open air audion, that is, an audion the electrodes of which are not inclosed in an evacuated vessel as distinguished from the audion the electrodes of which are inclosed and sealed in an evacuated bulb or tube.

Further objects of the invention Will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location and relative arrangement of parts, all as will be more fully hereinafter 'set forth, as shown by the accompanying drawing, and finally pointed out in the appended claims.

Referrin to the drawing,-

The sing e figure is a diagrammaticview of a radio receiving system with an open air audion detector or amplifier in circuit therewith.

It is among the special purposes of my present invention to provide an open air audion for use in radio telephony or telegraphy, and While, for the purposes of this present invention, 1 have shown the device associated With a receiving circuit, it is understood that my invention, as defined in the claims, is not limited to this use of the device, as the same may be employedin any and all instances where an audion is employed either as a detector, amplifier or oscillator.

In the drawing, A, L, C, E designate 'the antenna, inductance, capacity and earth, a respectively of the antenna receiving system the inductance L of which is associate through coil S of the series oscillating circuit S, C. The terminals of this oscillating circuit are connected, respectively, to the hot electrode F and the cold electrode G, preferably with a blocking condenser G inserted in the lead ofthe electrode G, as shown. The filament electrode F, in ac- A through impedance coil P.

cordance with my invention, is a Nernst glower which is heated from current source It will be noted the cold electrode G which in this instance is the grid electrode, surrounds the Nernst glower, and the plate or w1ng electrode W is in the form of a plate which surrounds both the grid and filament electrodes. The signal receiving device R is connected between thering and filament electrodes in series with the current source B in the usual manner.

Heretofore, it has been necessary to inclose the electrodes of the audion in an evacuated vessel for various reasons, one of them being that the filament electrode, bemg more commonly a carbon filament, would oxidize in the open air, and would immedlately burn-up. I have found that by employing a Nernst filament, this ob- JGCtlOll 1s overcome, and consequently an open air audion, as distinguished from the audion the electrodes of which are sealed in an evacuated vessel, can be employed.

Having now set forth the objects and nature of my invention, What I claim as new and useful, and of my own invention, and desire to secure by Letters Patent, is

1.An open air audion comprising a hot electrode and a plurality of cold electrodes all exposed to atmospheric conditions.

2. A device of the class described comprising a hot electrode and a plurality of cold electrodes all located in the open air, said cold electrodes bein located at relatively different distances rom said hot electrode.

3. A device of the class described comprising a Nernst filament electrode and a plurality of cold electrodes all exposed to atmospheric conditions.

4. A device of the class described comprising a Nernst filament electrode and a plurality of cold electrodes, said cold elecelectrodes vbeing co-axially located around said filament electrode, all of said electrodes prising a filament electrode, a grid electrode and a plate electrode, all of said electrodes being located in the open air, said grid and plate electrodes being co-axially located around said filament electrode, and said grid electrode being interposed between said plate and filament electrodes.

8. A device of the class described comprising a Nernst filament electrode, a grid electrode and a plate electrode all of said electrodes being exposed to the atmosphere. 9. A device of the class described comprising a Nernst filament electrode, a grid electrode and a plate electrode, said grid and plate electrodes around said Nernst filament electrode'all of coaxially located said electrodes being exposed to the open I prising a N ernst filament electrode, a grid electrode and a plate electrode, said grid and plate electrodes coaxially located around said Nernst filament electrode, and

said grid electrode being interposed between said plate and N ernst filament electrodes all of said electrodes being-exposed to the atmosphere.

llQThe combination with an audion, the electrodes of which being located in the open. air, of circuits associated with said electrodes.

I In testimony whereof I have hereunto set my hand on this 27th day of November, A. D. 1916. v

LEE DE FOREST. 

